1. Field of the Invention
This invention relates to a system for transferring power without direct contact through the use of high frequency electromagnetic induction. In particular, this invention relates to a contactless power supply that also transfers control information at the same time through the same mechanism that transfers the power.
2. The Prior Art
Machine slides are generally powered directly by a motor through wires that connect the stationary power supply to the motor on the moving part of the slide. Since in many applications, the slide moves back and forth hundreds of times during an operation, the wires tend to wear very easily, and require frequent replacement. In addition, the weight of the wires, especially with large slides, can add significantly to the power requirements, and increase the inertia of the moving part of the slide.
It is therefore desirable to power a slide or other mechanism without using wires between the moving and stationary parts. One way to do this is through electromagnetic induction. This method is shown in U.S. Pat. No. 5,737,211 to Hirai et al. This patent shows the operation of a moving slide having a toroid through which wires from the stationary platform are run. The current from the wires induces a current in the toroid, which powers the slide without direct contact between the wires and the slide itself. While this device is useful for some purposes, it does not provide a way for controlling the power over the same lines.